Description:
This invention relates to an instruction device for use in teaching the game of golf, and particularly to a signal device applicable to the back of the lower forearm or back of the uppermost or gripping hand on the club shaft to enable both the golfer and his instructor to monitor the position of the hand and wrist in the golf swing.
Generally speaking, it is common knowledge among golfers that the positioning of the hands upon the grip of the club shaft may differently affect the flight of the ball, assuming a swing reproducible in other respects. It is perhaps also equally generally understood that the arm of the uppermost or gripping hand, viz., the left arm of the right-handed golfer, is preferably straight throughout the swing. However, it is less well understood that the discipline of the left hand, as well as of the left arm and wrist, is equally important to the control of the path and attitude of the club head at impact, and therefore of the flight of the ball after impact with the club head.
It is therefore an object of this invention to provide a signal device readily applicable to the back of the gripping hand or lower forearm thereof to enable the instructor to teach, and the golfer to learn, respectively, the discipline of the left arm wrist and hand during the golf swing.
It is a further object to provide a device of the character described which will provide a distinct signal of proper hand position and attitude when viewed directly by the golfer at the address of the ball or upon making a visual inspection of his hands at various positions during the golf swing, and will also provide a different but equally distinct signal of proper hand position when viewed by the golfer practicing the swing before the instruction mirror.
The instruction device of this invention and its use for its intended purpose will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a top view of the device, seen separately and before attachment to the back of the arm or hand for its intended use;
FIG. 2 is an elevational view of the device;
FIG. 3 is a plan view of the back of the gripping hand showing the instruction device of the invention emplaced thereupon for use;
FIG. 4 is a side elevational view of the hand corresponding to FIG. 3, and illustrating the proper view of the device when monitored by the direct view of the golfer both at the address and at the top of the back swing;
FIGS. 5 and 6 are top and sectional elevational views respectively of the signal body of the invention constructed by an alternative procedure and providing a slightly modified form.
As indicated in the drawings, the instruction device of the invention is essentially a three-dimensional signal body 10 which is applicable to the back of the lower forearm or to the back of the club-gripping hand 12, or to the back of the glove upon that hand, and which has sufficient height above the plane of the back of the arm or hand to provide two distinct signals, one by the top surface 14 of the signal body when the device and the back of the arm or hand are viewed in a line of sight perpendicular to the back of the arm or hand 12, and a second distinct signal by the side walls 16 when the arm or hand 12 are viewed from the side, as in a line of vision in the plane of the back of the arm or hand, or in the plane of the flat top surface of the signal body.
Accordingly, the signal body preferably has a substantial height or thickness. It further is desirable that the device present one shape or one color when viewed from the top, and a distinct and contrasting shape or color when viewed from the side. Preferably, both shape and color will contrast between top and side views to avoid limitation of use by color blindness.
Within these criteria, I have found it convenient to make the signal body in the shape of a cylinder, which has the further advantage of a uniform appearance when viewed from any side, and thus eliminates any necessity for rotative orientation. For normal instruction purposes, I prefer to place the signal body a distance of approximately an inch toward the wrist from and directly in line with the base knuckle of the middle finger of the gripping hand when the hand is closed. This position is indicated in FIGS. 3 and 4 of the drawing. However, I have found that placement as high along the posterior of the forearm as the lower two inches of the distal end will yield a useful signal in the manner explained for placement upon the back of the hand. So also will placement closer to the knuckle, but then the danger of accidental dislodgement is greater.
To permit the signal body 10 to be readily attachable to and detachable from the skin or glove, I have provided the cylindrical body in one form as a plug having on its flat surface opposite the top signal surface 14 a self-sticking adhesive layer 18 which is normally covered during manufacture, packaging, and shipment with a protective outer layer or film 20 which is readily releasable by the adhesive layer 18 to expose the adhesive for attachment of the signal body to the back of the hand or glove. This may readily be achieved by the use of commercially available double-coated adhesive films, one coating attaching the film to the under-surface of the plug and the opposite coated face having thereon the protective layer whose removal activates or readies the outer adhesive layer 18 for attachment either to the glove or directly to the skin.
In order to provide a visual signal not only at various check points in the swing, but also during a continuous swing executed in the usual manner, the signal body must withstand substantial acceleration without dislodgement especially during the down swing. For that reason and also to prevent unintended interference with the golfer's swing, the signal body 10 preferably has substantially negligible mass relative to the mass of the club and moving body parts, and also in the present context, in relation to the adhesive force available to maintain the signal body in position.
While this may be readily accomplished in a number of ways that may suggest themselves, I contemplate two that are very serviceable. In one, I fabricate the signal body from a low density foamed plastic. Such material lends itself readily to die cutting, is readily grippable in the fingers, and has only insignificant weight in signal body sizes found adequate for the purpose. For example, in the form shown, the signal body may be die cut as a plug from a slab of foamed plystyrene which is substantially rigid and may have a density as low as a pound or so per cubic foot. Because this material is commercially available as a white material, it serves in its available state to provide a very adequate signal when its interior is exposed by the die cutting of the slab. It is therefore convenient to apply to one surface of the slab before cutting the double-coated adhesive film that provides the adhesive attaching layer 18 and on the opposite surface of the slab a brightly colored layer or film suitably adhered thereto to become the top signal surface 14. I have found a bright orange-red paper very adequate for this purpose because of its clear contrast with the brilliant white of the cut plastic foam surfaces that form the sidewalls 16.
In a second form, shown in FIGS. 5 and 6, the signal body 10' is thermo-vacuum formed from sheet plastic material, the essentially cylindrical preferred shape being provided as an inverted cup-like shell drawn integrally from a blank of the sheet plastic material, with a slight draft to facilitate unmolding, and trimmed from the blank so as to have a narrow flange 11, of, say one to two millimeters in width. The flange 11 is provided with at least two holes 13 as shown to facilitate the attachment of the signal body 10' to the back of the glove with a couple of tacking stitches, using needle and thread.
If the sheet plastic is very thin it may be reinforced by a cover 17 of similar material to close the open end of the cup, the same being secured either adhesively or by heat-seal to the attaching flange 11. The cover 11 also provides an extensive base for an attaching adhesive layer 18' as already explained in connection with the foam plug form of FIGS. 1 and 2.
The second form is also susceptible of mass manufacture from plastic, the contrasting orange-red color of the top 14' of the body being applied selectively to the white plastic blank by screening, and the sheet registered in a multiple mold in which many of the cup-like bodies 10' are formed simultaneously. The covers 17 and adhesive layers 18' are likewise laminated en masse to the drawn multiple cup sheet as single sheets, and the signal bodies die-trimmed from the laminated sheets.
It will be seen, therefore, that the signal body, both as above described generally and as illustrated specifically in the drawings, is adapted to provide both by the contrasting colors of its top and side signal surfaces, as well as by their contrasting shapes, a clear signal to the golfer in checking the positioning of his hands at various points in the golf swing, whether he views them by direct line of sight or indirectly with the use of the practice mirror. When the gripping hand is properly positioned on the club shaft and extends straight from the arm without any back bending of the wrist, the golfer should see his gripping hand as in FIG. 4, both at the address and at the top of the back swing, i.e., with the signal body thereon viewed only from the side and with none of the top surface visible. In terms of the colors as above described that I have found particularly useful, i.e., the bright orange-red top signal, and the white side signal of the foamed plastic of the preferred embodiment, if the golfer "sees white, he's right". Conversely, should he be using the practice mirror and checking the hand position at the top of the back swing in that manner, he should see only the contrasting bright red top of the signal body, and none of its white side surface. Contrasting bright colors, although not essential, are desired because in addition to their direct visibility they are readily visible under cruder reflective conditions, such, for example, as the practicing of the golf swing with or without club in the privacy of the home using a picture window or the like as a practice mirror.
The features of the invention believed novel and patentable are set forth in the following claims: